1. Field of the Invention.
This invention relates generally to concrete products forming machines (CPM), and more particularly to structures and methods for assisting in the exchange of one mold assembly with another within such machines.
2. Description of the Prior Art.
Prior art machines for forming concrete products within a mold box include a product forming section comprising a stationary frame, an upper compression beam and a lower stripper beam. The mold assembly includes a head assembly that is mounted to the compression beam, and a mold box that is mounted on a vibration system and receives concrete material from a feed drawer. An example of such a system is shown in U.S. Pat. No. 5,807,591 which describes an improved concrete products forming machine (CPM) assigned in common to the assignee of the present application and herein incorporated by reference for all purposes.
In use, the feed drawer moves concrete material over the top of the mold box and dispenses the material into the contoured cavities of the mold box. The feed drawer typically includes an agitator assembly within the drawer that operates to break up the concrete and improve its consistency prior to dropping it into the mold box. As the concrete material is dispensed, a vibration system shakes the mold box to spread the concrete material evenly within the mold box cavities in order to produce a more homogeneous concrete product. A wiper assembly, mounted to the front of the feed drawer, acts to scrape excess concrete from the shoes of the mold head assembly when the feed drawer is moved to and from an operative position above the mold box.
After the concrete is dispensed into the mold cavities, the feed drawer retracts from over the top of the mold box. A spreader, bolted separately to the front of the feed drawer, scrapes off excess concrete from the top of the mold when the feed drawer is retracted after filling the mold cavities. The compression beam then lowers, pushing shoes from the head assembly into corresponding cavities in the mold box. The shoes compress the concrete material during the vibration process. After compression is complete, the stripper beam lowers together with the compression beam as the head assembly pushes further into the cavities against the molded material. A molded concrete product thereby emerges from the bottom of the mold assembly onto a pallet and is conveyed away for curing and a new pallet moved in its place beneath the underside of the mold assembly.
The mold box and head assembly are matched together and configured to form concrete products in a specific shape, size, and number. Each product configuration requires a different mold. When the operator desires the CPM to produce products in different configurations, the mold box must be detached from mounts on the CPM and removed along with the head assembly. A different mold box and head assembly must then be moved into place and mounted within the CPM.
Conventional methods for changing molds out in a CPM are typically labor intensive and result in a lot of downtime with the machine, leading to lost revenue. Accordingly, there is need for an improved system and method for better automating the process for changing molds within a concrete products forming machine that minimizes these drawbacks.